Random XP Pro freezes & crashes - help needed, out of ideas

Hi tech gurus,

My first post, so apologies if my etiquette isn't perfect!

I have an XP Pro SP2 system with an Athlon 3400 and 512mb PC3200 RAM and a Radeon 9500, with an 80Gb Samsung Spinpoint HDD in an Ideq 210P SFF chassis.

Since January I have been experiencing apparently random crashes when I run any apps which seem to use a reasonable amount of RAM or do any CPU work.

I have reinstalled the OS & SP, swapped the HDD for an older one and reinstalled XP Pro, SP2 and drivers, virus scanned, rootkit scanned, spyware scanned and run a number of registry fix programs. Nothing worked.

I took my system to my local PC system builder who actually seems to understand all these configuration issues (not the frequently encountered small time system builder and professional shrugger when presented with something tricky). He ran some diagnostics, swapped the CPU and RAM and tried them in other systems, and found no problem. This only left the MB and chassis which he couldn't test, so I returned the system under warranty and had it repaired. I don't know what was supposed to have been fixed, but it looks like a new MB to me.

Same problem has occurred though. I've run Memtest and found no fault.

Sometimes the system freezes, sometimes it just reboots. When I get a reboot, there is a System error entry (category 102, event 1003) in the event log which seems to be the culprit which says something to the effect of:-

Error code 10000050, parameter1 b786eb1c, parameter2 00000001, parameter3 bf87b6c6, parameter4 00000000.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

This seems to be a kernel error.

Each time the system restarts, I get a dialog box with this message:-

Microsoft Windows The system has recovered from a serious error. A log of this error has been...

I've tried the link and it doesn't seem to have a KB entry to cover my situation.

I'm completely out of ideas now, I think there may be some sort of driver conflict, but don't know where to start. I have a minidump error which I can post if there is anyone out there who thinks they may be able to work out what is going on.

Any help would be greatly appreciated!

what aboutheat issues? what are your temps like in that small form factor chassis? what kind of cooling do you have for the chassis? also what about the PSU? what brand and what wattage? have you checked the voltages to see if they are stable?

Lots of people suggested heat, and it's a totally logical suggestion. I have a smart system monitoring app which monitors the temperature constantly and adjusts the fan speed to compensate.

Temperature doesn't normally go above 55 degrees c. The case doesn't feel hot either.

If the PC isn't doing anything, I can leave it on for hours. It seems to be when running apps that the system falls over. Firefox will crash it, Poser will crash it, Acronis True Image crashed it, Outlook crashed it, AVG antivirus scan crashed it. The thing is that these are not consistent. Sometimes it will run the Sims2 for a couple of hours without problem, on other occasions, the system will have just started, I'll start Firefox, and bam, instant reboot.

I had the CPU checked, and the thermal grease replaced. CPU worked fine in another box.

It worked just fine until January. I upgraded my video card drivers, and got the odd crash, so I used the previous ones to see if that was the problem. No change. I have downloaded the latest drivers, and can't see why these should be problematic. I have tried 4 different builds and nothing works any better.

If it isn't hardware, perhaps it's BIOS configuration, but I loaded the optimised defaults, and this didn't make any difference either. Voltages are all optimised presets in the BIOS.

I'm normally fairly good at problem solving ( I have never had anything I couldn't fix previously on either my or a number of other people's PCs), but this thing is several levels of complexity beyond me. I have tried everything I know, done some research, learned some more stuff and tried to isolate or repeat the crashes, but they seem to be linked to system activity.

I'm a bit concerned that if I send the chassis back, the tech guys will just run some cursory tests and say that they can't find a problem, and I'll end up paying yet more money for a system I can't get to work.

I just think it has to be a basic hardware issue or a problem with a driver/BIOS/OS conflict. Haven't tried safe mode though. Maybe that's the next stage.

Tried safe mode, still crashes/locks up.
Back to where I was I guess...

You seem to have been pretty through in troubleshooting the problem. it definetely sounds like a hard ware problem. have you tried setting the Bios to default settings? apart from that MY guess would be either the video card is going bad or the mobo is.